RT-AX11000 with Century Link Fiber?

I couldn’t find anything about this on the forums so hopefully this isn’t a repeat thread. I am trying to get rid of the crappy Century Link supplied mode/router and I know that it is possible. Not sure what I am doing wrong. I set it up for PPPoE, I got all my login info for that. I have everything plugged in properly. I have VLAN tagging turned on. I am using the default firmware as I heard there is no Merlin version that works with my router. Any thoughts? Any help is very much appreciated. If you guys need more info let me know. Thank you!